Can you help me about the meaning of the value of these variables?lu_index in my Grads results 1-18What does it mean that the numbers 1 to 18?and then i display the variable of vegfradisplays the results of 52 455, 44 343 and otherswhether the meaning of these figures shows that the amount of land area covered by vegetation? if yes what is the unit?if not what the real meaning of these figures?